1. Field of the Invention
This invention relates to an apparatus for shielding molten metal during teeming and to a carriage provided with such apparatus.
2. Description of the Prior Art
The desirability and one apparatus for shielding molten metal during a teeming operation are described in U.S. Pat. No. 4,023,614.
To accomplish shielding or teem stream protection as it is sometimes called requires excursion of the ambient atmosphere (usually air) from contact with the molten metal stream. This is usually accomplished by surrounding the stream with a gas that will not react with the molten metal to form harmful reaction products that become trapped in the solidified metal. Such inert (to the metal) gases include argon and helium among others. To confine the gas prior art workers have designed devices to, in effect, form a continuous wall around and spaced apart from the molten stream with means to introduce the inert gas into the space between the wall stream.
Examples of such prior art devices are shown in U.K. Pat. Nos. 1,363,111; 1,086,094, 1,371,880, 1,480,944, 1,468,528, 1,525,039, 1,372,801, 1,221,545, 1,079,560, 781,276 and 781,277.